Compressor turbine wheel

ABSTRACT

A turbine wheel for a gas turbine engine including a compressor impeller and a radial inflow turbine integral to or attached to the compressor impeller is provided. A compressor turbine wheel including features to increase surface area of a surface of the compressor impeller and/or the radial inflow turbine and/or a passage to flow air between the compressor impeller and the radial inflow turbine is further provided. Methods for cooling radial inflow turbines integral to compressor impellers are further provided.

TECHNICAL FIELD

This disclosure relates to gas turbine engines, and, more specifically,to compressor turbine wheels of gas turbine engines.

BACKGROUND

Gas turbine engines are used on vehicles such as airplane andhelicopters. These engines are internal combustion engines that operateto produce thrust by discharging a high velocity exhaust. Some gasturbine engines may also include fan blades to create thrust.

Gas turbine engines include one or more compressors, a combustor and oneor more turbines. Air is compressed in the compressor(s), mixed withfuel in the combustor and ignited, such that exhaust gases are createdand discharged through a turbine to create thrust. The exhaust gasrotates the turbine, which is typically used to turn a shaft and produceshaft work output, such as to drive the compressor or a gearbox. Theremay be one or more turbines and corresponding shafts producing shaftwork output. Systems within a gas turbine engine may use the shaft workoutput.

Some existing gas turbine engine compressor impellers and radial inflowturbines have various shortcomings, drawbacks, and disadvantagesrelative to certain applications. Accordingly, there remains a need forfurther contributions in this area of technology.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure may be better understood with reference to thefollowing drawings and description. The components in the figures arenot necessarily to scale. Moreover, in the figures, like-referencednumerals designate corresponding parts throughout the different views.

FIG. 1 illustrates a diametrical, forward-aft axial cross-sectional viewof an example of a compressor turbine wheel;

FIG. 2 illustrates a diametrical, forward-aft axial cross-sectional viewof another example of a compressor turbine wheel;

FIG. 3 illustrates a diametrical, forward-aft axial cross-sectional viewof yet another example of a compressor turbine wheel;

FIG. 4 illustrates a diametrical, forward-aft axial cross-sectional viewof yet another example of a compressor turbine wheel;

FIG. 5 illustrates a side view of yet another example of a compressorturbine wheel;

FIG. 6 illustrates a forward view of the example of a compressor turbinewheel of FIG. 5;

FIG. 7 illustrates an aft view of the example of a compressor turbinewheel of FIG. 5; and

FIG. 8 illustrates a top perspective view of the example of a compressorturbine wheel of FIG. 5.

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION

According to an example of the present disclosure, a compressor turbinewheel is rotatable about a forward-aft axis. The compressor turbinewheel includes a compressor impeller and a radial inflow turbine aft ofthe compressor impeller. The compressor turbine wheel includes aforward-axial wheel bore circumferentially about the forward-aft axis.The compressor impeller includes a forward impeller vane inlet, a radialimpeller vane outlet configured to flow compressed air radially outwardto a diffuser, an aft inner surface extending from the forward impellervane inlet to the radial impeller vane outlet, and inner vane side wallsprojecting forward from the aft inner surface. The radial inflow turbineincludes a radial turbine vane inlet configured to receive combustiongases from a combustor, an aft turbine vane outlet, a forward innerturbine surface extending from the radial turbine vane inlet to the aftturbine vane outlet, and inner turbine vane side walls projecting aftfrom the forward inner turbine surface. The radial inflow turbine isintegral to the compressor impeller so as to be a combined compressorimpeller and radial inflow turbine. Alternatively, the radial inflowturbine is fixed to the compressor impeller to form a combinedcompressor impeller and radial inflow turbine. The aft inner surfaceand/or the inner vane side walls may include one or more ribs configuredto increase surface area of the aft inner surface and/or the inner vaneside walls. The forward inner turbine surface and/or the inner turbinevane side walls may include one or more pins, one or more ribs, one ormore vanes, and/or one or more turbulators configured to increasesurface area of the forward inner turbine surface. A passage may extendbetween the aft inner surface and the forward inner turbine surface, thepassage configured to direct flow of air between the compressor impellerand the radial inflow turbine. The compressor turbine wheel may beconfigured to cool the radial inflow turbine by conduction from theradial inflow turbine to the compressor impeller. The compressor turbinewheel may be for example, cast, injection-molded, or printed.

According to another example of the present disclosure, a compressorturbine wheel is rotatable about a forward-aft axis passing through aforward-aft axial wheel bore at a center of the compressor turbinewheel. The compressor turbine wheel includes a compressor impeller and aradial inflow turbine aft of the compressor impeller. The compressorimpeller includes a forward impeller vane inlet, a radial impeller vaneoutlet configured to flow compressed air radially outward to a diffuser,an aft inner surface extending from the forward impeller vane inlet tothe radial impeller vane outlet, and inner vane side walls projectingforward from the aft inner surface. The radial inflow turbine includes aradial turbine vane inlet configured to receive combustion gases from acombustor, an aft turbine vane outlet, a forward inner turbine surfaceextending from the radial turbine vane inlet to the aft turbine vaneoutlet, and inner turbine vane side walls projecting aft from theforward inner turbine surface. The radial inflow turbine is integral tothe compressor impeller, or an aft outer surface of the compressorimpeller is fixed to a forward outer surface of the radial inflowturbine. A passage extends between the aft inner surface and the forwardinner turbine surface.

According to yet another example of the present disclosure, a method ofcooling a radial inflow turbine of a gas turbine engine rotatable abouta forward-aft axis, comprising: transferring heat from the radial inflowturbine to a compressor impeller via conduction through the radialinflow turbine and the compressor impeller. The radial inflow turbine isintegral to the compressor impeller, or an aft outer surface of thecompressor impeller is fixed to a forward outer surface of the radialinflow turbine.

One interesting feature of the devices and methods described hereinbelow may be to decrease the physical dimensions of combined compressorimpellers and radial inflow turbines. Alternatively, or in addition, aninteresting feature of the devices and methods described herein belowmay be that the cost of combined compressor impellers and radial inflowturbines is less than conventional arrangements. Alternatively, or inaddition, an interesting feature of the devices and methods describedherein below may be that unwanted impeller deflection, or “flowering,”is reduced, which may consequently result in tighter tip clearances andimproved performance. Alternatively, or in addition, an interestingfeature of the devices and methods described herein below may be theshort travel path for cooling flow of air, which does not necessitateany pipes or manifolds. Alternatively, or in addition, an interestingfeature of the devices and methods described herein below may beretention of circulating air in the combined compressor impellers andradial inflow turbines. Alternatively, or in addition, an interestingfeature of the devices and methods described herein below may be thatthe diameters of the compressor impellers and the diameters of theradial inflow turbines of the combined compressor impellers and radialinflow turbines do not need to be the same, and the diameters of thecompressor impellers and radial inflow turbines may be set for maximumcycle efficiency.

For purposes of promoting an understanding of the principles of thedisclosure, reference will now be made to the examples illustrated inthe drawings, and specific language may be used to describe the same. Itwill nonetheless be understood that no limitation of the scope of thedisclosure is intended by the illustration and description of certainexamples of the disclosure. In addition, any alterations and/ormodifications of the illustrated and/or described example(s) arecontemplated as being within the scope of the present disclosure.Further, any other applications of the principles of the disclosure, asillustrated and/or described herein, as would normally occur to oneskilled in the art to which the disclosure pertains, are contemplated asbeing within the scope of the present disclosure.

FIG. 1 illustrates a diametrical, forward-aft axial cross-sectional viewof an example of a compressor turbine wheel 100 of a gas turbine engine.Compressor turbine wheel 100 includes compressor impeller 102, wheelbody 124, and radial inflow turbine 104. Compressor impeller 102 mayinclude forward impeller vane inlet(s) 114, radial impeller vaneoutlet(s) 116, a forward impeller case surface 118 extending fromforward impeller vane inlet(s) 114 to radial impeller vane outlet(s)116, an aft inner surface 120 extending from forward impeller vaneinlet(s) 114 to radial impeller vane outlet(s) 116, and inner vane sidewalls 122 extending between forward impeller case surface 118 and aftinner surface 120. Radial inflow turbine 104 includes radial turbinevane inlet(s) 126, aft turbine vane outlet(s) 128, a forward innerturbine surface 130 extending from radial turbine vane inlet(s) 126 toaft turbine vane outlet(s) 128, an aft turbine case surface 132extending from radial turbine vane inlet(s) 126 to aft turbine vaneoutlet(s) 128, and inner turbine vane side walls 134 extending betweenforward inner turbine surface 130 and aft turbine case surface 132.

Compressor turbine wheel 100 is rotatable about forward-aft axis 112.Compressor turbine wheel 100 is circular when viewed from the forwarddirection or the aft direction, with the forward-aft axis 112 passingthrough a forward-aft axial wheel bore circumferentially aboutforward-aft axis 112 at the center of compressor turbine wheel 100 whenviewed from the forward direction or the aft direction. The wheel borehas a diameter 136. Compressor turbine wheel 100 has a radius extendingperpendicularly from forward-aft axis 112, including, for example, alongradius 140.

Compressor impeller 102 may be any rotating component configured totransfer energy from a power source driving the component rotation to afluid being pumped by accelerating the fluid outward from the center ofrotation. Compressor impeller 102 may be a short cylinder with an openinlet (such as forward impeller vane inlet(s) 114) configured to acceptthe incoming fluid and vanes to push the fluid radially outward.Compressor impeller 102 may have approximately a curved cone shape.

Radial inflow turbine 104 may be any turbine in which flow of the fluidin the turbine is radially outward with respect to the shaft, andsmoothly orientated perpendicular to the rotation axis. Radial inflowturbine 104 of compressor turbine wheel 100 is configured to be cooledby conduction of heat to compressor impeller 102. Radial inflow turbine104 may have approximately a curved cone shape.

Compressor impeller 102 is integral to wheel body 124 and radial inflowturbine 104 is integral to wheel body 124. Radial inflow turbine 104 isconsequently integral to compressor impeller 102.

Radial impeller vane outlet(s) 116 is configured to flow compressed airradially outward to a diffuser 106. Air may then flow from diffuser 106to deswirler 108. Air then enters combustor 110.

During operation of compressor turbine wheel 100, fluid flows intocompressor impeller 102 through forward impeller vane inlet(s) 114 andinto vane(s) of compressor impeller 102. As compressor turbine wheel 100rotates, fluid in compressor impeller 102 may increase in pressure.Fluid flows out of compressor impeller 102 through radial impeller vaneoutlet(s) 116. Fluid may then flow radially outward to diffuser 106.Fluid flows from diffuser 106 to deswirler 108. After exiting deswirler108, fluid may flows to space adjacent and radially outward of combustor110. Fluid may then enter combustor 110. Fluid, which may includecombustion gases, exits combustor 110 and may then flow through radialturbine vane inlet(s) 126 into radial inflow turbine 104. As compressorturbine wheel 100 rotates, fluid in radial inflow turbine 104 mayincrease in turbulence. Fluid flows out of radial inflow turbine 104through aft turbine vane outlet(s) 128.

Radial turbine vane inlet(s) 126 is configured to receive combustiongases from combustor 110.

FIG. 2 illustrates a diametrical, forward-aft axial cross-sectional viewof another example of a compressor turbine wheel 200. Compressor turbinewheel 200 includes many of the same components performing the samefunctions as those described herein elsewhere. In the illustratedexample, compressor turbine wheel 200 includes separately manufacturedcompressor impeller 102 and radial inflow turbine 104 that are attachedtogether by techniques such as bonding, welding, friction welding,brazing, and/or any other type of mechanical coupling. Radial inflowturbine 104 is attached to compressor impeller 102 at an aft outersurface 208 of compressor impeller 102 by a forward outer surface 206 ofradial inflow turbine 104. Aft outer surface 208 of compressor impeller102 is fixed to forward outer surface 206 of radial inflow turbine 104.One or more surfaces of compressor turbine wheel 200 may include rib(s)210 projecting outward from the one or more surfaces. A passage 202extends between aft inner surface 120 and forward inner turbine surface130.

Aft inner surface 120 may include rib(s) 210 projecting outward from aftinner surface 120 configured to increase surface area of aft innersurface 120. Rib(s) 210 may project in a forward direction from aftinner surface 120 in concentric arcs at different radii aboutforward-aft axis 112. Rib(s) 210 may project outward from inner vaneside walls 122 configured to increase surface area of inner vane sidewalls 122.

Rib(s) 210 may project in an aft direction from forward inner turbinesurface 130 in concentric arcs at different radii about forward-aft axis112 and/or from inner turbine vane side walls 134 configured to increasesurface area of forward inner turbine surface 130 and/or inner turbinevane side walls 134.

Passage 202 is configured to direct flow of air between compressorimpeller 102 and radial inflow turbine 104 and may be configured toprovide cooling air directly to radial inflow turbine 104 as illustratedby arrow 212 shown in FIG. 2. Passage 202 may vary in diameter or widthand have a cross-sectional shape and path as is necessary, desirable, orpreferable to achieve beneficial flow of air through passage 202.Passage 202 may pass straight through compressor impeller 102 and radialinflow turbine 104 along a line that is parallel to forward-aft axis 112as shown in FIG. 2, or take a less direct path through compressorimpeller 102 and radial inflow turbine 104.

Vane(s) 204 in radial inflow turbine 104 are surfaces within the turbinevanes configured to increase surface area and direct flow of air throughradial inflow turbine 104 to cool radial inflow turbine 104 and aftthrough aft turbine vane outlet 128 as illustrated by arrows 214 shownin FIG. 2.

During operation of compressor turbine wheel 200, fluid flows throughinto compressor impeller 102 through forward impeller vane inlet(s) 114and into vane(s) of compressor impeller 102. As compressor turbine wheel200 rotates, fluid in compressor impeller 102 may increase in pressure.Fluid flows out of compressor impeller 102 through passage 202, asillustrated by arrows 212, bypassing diffuser 106, deswirler 108, andcombustor 110 to provide cooling air directly to turbine vane(s) ofradial inflow turbine 104. As compressor turbine wheel 100 rotates,fluid in compressor impeller 102 may increase in turbulence as it passesthrough vane(s) 204 as illustrated by arrows 214. Fluid flows out ofradial inflow turbine 104 through aft turbine vane outlet(s) 128.

FIG. 3 illustrates a diametrical, forward-aft axial cross-sectional viewof yet another example of a compressor turbine wheel 300. Compressorturbine wheel 300 includes many of the same components performing thesame functions as those described herein elsewhere. Compressor turbinewheel 300 includes a passage 302 and a passage 304 extending between aftinner surface 120 and forward inner turbine surface 130. Aft turbinevane outlet 308 may be sealed so as to circulate air back to compressorimpeller 202, though radial inflow turbine 104 may still provide forcombustion gases to separately exit radial inflow turbine 104. Radialinflow turbine 104 may include vane(s) 306. Radial inflow turbine 104may include bump(s) 310 on forward inner turbine surface 130.

Vane(s) 306 in radial inflow turbine 104 are surfaces within the turbinevanes configured to increase surface area and direct flow of air throughradial inflow turbine 104 to cool radial inflow turbine 104 and aftthrough aft turbine vane outlet 128 as illustrated by arrows 312 shownin FIG. 3.

Passage 302 is configured to direct flow of air from compressor impeller102 to radial inflow turbine 104 as illustrated by arrows 312 in FIG. 3.Passage 304 also extends between aft inner surface 120 and forward innerturbine surface 130 configured to return flow of air from radial inflowturbine 104 back to compressor impeller 102 as illustrated by arrows 312in FIG. 3. Passages 302, 304 may vary in diameter or width and have across-sectional shape and path as is necessary, desirable, or preferableto achieve beneficial flow of air through passages 302, 304. Incompressor turbine wheel 300, passage 302 is radially outward relativeto passage 304. In other examples, passage 304 may be radially outwardrelative to passage 302. In yet other examples, passage 302 and passage304 may be equidistant from forward-aft axis 112. In still otherexamples, a compressor turbine wheel 300 may include more than twopassages extending between compressor impeller 102 and radial inflowturbine 104.

Bump(s) 310 may also be located on inner turbine vane side walls 134.Bump(s) 310 may be configured to increase surface area of forward innerturbine surface 130 and/or inner turbine vane side walls 234 andconsequently increase turbulence of air flowing through radial inflowturbine 104.

During operation of compressor turbine wheel 300, fluid flows throughinto compressor impeller 102 through forward impeller vane inlet(s) 114and into vane(s) of compressor impeller 102. As compressor turbine wheel200 rotates, fluid in compressor impeller 102 may increase in pressure.Fluid flows out of compressor impeller 102 through passage 302,bypassing diffuser 106, deswirler 108, and combustor 110 to providecooling air directly to turbine vane(s) of radial inflow turbine 104. Ascompressor turbine wheel 100 rotates, fluid in compressor impeller 102may increase in turbulence as it passes through vane(s) 306 asillustrated by arrows 312. Fluid flows from radial inflow turbine 104back to compressor impeller 102 through passage 304, such that,advantageously, cooling fluid is conserved.

FIG. 4 illustrates a diametrical, forward-aft axial cross-sectional viewof yet another example of a compressor turbine wheel 400. Compressorturbine wheel 400 includes many of the same components performing thesame functions as those described herein elsewhere. Compressor turbinewheel 400 includes forward impeller vane inlet(s) 402 and aft turbinevane outlet(s) 408 that may have the same or different diameters, as isnecessary, desirable, or preferable to maximize cycle efficiency.Forward inner turbine surface 130 may include turbulator(s) 510projecting outward from forward inner turbine surface 130.

Radial impeller vane outlet(s) 404 may be radially inward or radiallyoutward relative to radial turbine vane inlet(s) 406, as a consequenceof the diameter of compressor impeller 102 being less or greater,respectively, than the diameter of radial inflow turbine 104, as isnecessary, desirable, or preferable to maximize cycle efficiency.Alternatively, compressor impeller 102 may have the same diameter asradial inflow turbine 104, and radial impeller vane outlet(s) 404 maynot be radially inward or radially outward relative to radial turbinevane inlet(s) 406.

Turbulator(s) 410 may be any device configured to turn a laminarboundary layer of fluid into a turbulent boundary layer. Turbulator(s)410 may additionally be configured to increase surface area of forwardinner turbine surface 130 and increase turbulence of air flowing throughradial inflow turbine 104. Turbulator(s) 410 may project in an aftdirection. Turbulator(s) 410 may project outward from inner turbine vaneside walls 134 configured to increase surface area of inner turbine vaneside walls 134 and consequently increase turbulence of air flowingthrough radial inflow turbine 104.

During operation of compressor turbine wheel 400, fluid flows throughinto compressor impeller 102 through forward impeller vane inlet(s) 114and into vane(s) of compressor impeller 102. As compressor turbine wheel100 rotates, fluid in compressor impeller 102 may increase in pressure.Fluid flows out of compressor impeller 102 through radial impeller vaneoutlet(s) 116. Fluid may then flow radially outward to diffuser 106.Fluid flows from diffuser 106 to deswirler 108. After exiting deswirler108, fluid may flows to space adjacent and radially outward of combustor110. Fluid may then enter combustor 110. Fluid, which may includecombustion gases, exits combustor 110 and may then flow through radialturbine vane inlet(s) 126 into radial inflow turbine 104. As compressorturbine wheel 100 rotates, fluid in compressor impeller 102 may increasein turbulence. Turbulator(s) 410 may increase turbulence of fluid inradial inflow turbine 104. Fluid flows out of radial inflow turbine 104through aft turbine vane outlet(s) 128.

FIG. 5 illustrates a side view of yet another example of a compressorturbine wheel 500. Compressor turbine wheel 500 includes compressorimpeller 502 and radial inflow turbine 504. Compressor impeller 502includes forward impeller vane inlets 506, radial impeller vane outlets508, an aft inner surface 514 extending from forward impeller vaneinlets 506 to radial impeller vane outlets 508, and inner vane sidewalls 516 projecting forward from aft inner surface 514. Radial inflowturbine 504 includes radial turbine vane inlets 512, aft turbine vaneoutlets 510, a forward inner turbine surface 518 extending from radialturbine vane inlets 512 to aft turbine vane outlets 510, and innerturbine vane side walls 520 projecting aft from forward inner turbinesurface 518. Compressor turbine wheel 500 is rotatable about forward-aftaxis 524. Compressor turbine wheel 500 is circular when viewed from theforward direction as in FIG. 6 or the aft direction as in FIG. 7, withthe forward-aft axis 524 passing through a forward-aft axial wheel bore522 circumferentially about forward-aft axis 524 at the center ofcompressor turbine wheel 500 when viewed from the forward direction asin FIG. 6 or the aft direction as in FIG. 7. FIG. 8 illustrates a topperspective view of compressor turbine wheel 500.

During operation of compressor turbine wheel 500, fluid flows intocompressor impeller 502 through forward impeller vane inlets 506 andinto vane(s) of compressor impeller 502. As compressor turbine wheel 500rotates, fluid in compressor impeller 502 may increase in pressure.Fluid flows out of compressor impeller 502 through radial impeller vaneoutlets 508. Fluid may then flow radially outward to diffuser 106. Fluidflows from diffuser 106 to deswirler 108. After exiting deswirler 108,fluid may flows to space adjacent and radially outward of combustor 110.Fluid may then enter combustor 110. Fluid, which may include combustiongases, exits combustor 110 and may then flow through radial turbine vaneinlets 512 into radial inflow turbine 504. As compressor turbine wheel500 rotates, fluid in radial inflow turbine 504 may increase inturbulence. Fluid flows out of radial inflow turbine 504 through aftturbine vane outlets 510.

A gas turbine engine that includes compressor turbine wheel 100 maysupply power to and/or provide propulsion of an aircraft. Examples ofthe aircraft may include a helicopter, an airplane, an unmanned spacevehicle, a fixed wing vehicle, a variable wing vehicle, a rotary wingvehicle, an unmanned combat aerial vehicle, a tailless aircraft, a hovercraft, and any other airborne and/or extraterrestrial (spacecraft)vehicle. Alternatively or in addition, a gas turbine engine may beutilized in a configuration unrelated to an aircraft such as, forexample, an industrial application, an energy application, a powerplant, a pumping set, a marine application (for example, for navalpropulsion), a weapon system, a security system, a perimeter defense orsecurity system.

A gas turbine engine may operate with a convertible configuration ineither a turbofan mode or a turboshaft mode. The gas turbine engine maytake a variety of forms in various embodiments. In some forms, the gasturbine engine may be a turbojet or turboprop engine with a convertibleconfiguration. Furthermore, the gas turbine engine may be an adaptivecycle and/or variable cycle engine. Other variations are alsocontemplated.

The gas turbine engine may include a forward intake section, acompressor section, a combustion section, a turbine section, and an aftexhaust section. As noted above, the hot, high pressure fluid exitingthe impeller and combustor passes through the turbine section duringoperation of gas turbine engine. As the fluid flows through the turbinesection, the fluid passes between blades of the turbine causing theturbine to rotate. The rotating turbine may turn the shaft such that theblades may rotate around an axis of rotation, such as the centerline ofthe gas turbine engine. The blades of the turbine may extend radiallyoutward from the centerline of the turbine and rotate circumferentiallyrelative to the centerline.

The terms “brazing,” “brazed,” and “braze,” unless stated otherwise,alone or in combination with other terms, refer to a metal-joiningprocess known in the art in which two or more surfaces that are free ofoxides are joined together by melting a flowing a filler metal into thejoint, the filler metal having a lower melting point than the adjoiningtwo or more surfaces. The process of “brazing” does not involve meltingthe two or more surfaces together. Further, the process of “brazing”requires that the two or more surfaces are much more closely fittedsurfaces than in soldering. During the process of “brazing,” the fillermetal flows into the gap between the closely fitting two or moresurfaces by capillary action.

The terms “welding,” “welded,” and “weld,” unless stated otherwise,alone or in combination with other terms, refer to a metal-joiningprocess known in the art in which two or more surfaces are melted,joined together, and allowed to cool once together, causing fusion. Inaddition to melting the base metal surfaces, a filler material is oftenadded to the joint to form a pool of molten material that cools to forma joint that may be stronger than the base material. Pressure may alsobe used in conjunction with heat to produce a weld.

The term “aft,” as used herein, unless stated otherwise, alone or incombination with other terms, refers to an element, surface, or assemblybeing situated at, near, or toward a tail of an aircraft of othervehicle. The term “aft” may be distinguished from the term “forward,”which, as used herein, unless stated otherwise, alone or combinationwith other terms, refers to an element, surface, or assembly beingsituated at, near, or toward a front of an aircraft or other vehicle.The forward and aft directions may refer to opposite directions along anaxis, which may be parallel to, or identical to, a centerline of a gasturbine engine and/or forward-aft axis 112. The terms “axial” and“axially,” as used herein, unless stated otherwise, alone or incombination with other terms, refers to elements, surfaces, andassemblies along a common axis, which may be forward or aft relative toother elements, surfaces, and/or assemblies.

The terms “radially” and “radial,” as used herein, unless statedotherwise, alone or in combination with other terms, refer to elements,surfaces, or assemblies relative to one another along a radius, such asradius 140, or parallel to or coplanar with radius 140, that may projectperpendicularly from a centerline axis, which may be parallel to, oridentical to, a centerline of a gas turbine engine and/or forward-aftaxis 112. The terms “inward” and “inwardly,” as used herein, unlessstated otherwise, alone or combination with other terms, refer to anelement, surface, or assembly being situated at, near, or toward thecenterline axis along a radius, which may be radius 240 or parallel toor coplanar with radius 240. The terms “outward” and “outwardly,” asused herein, unless stated otherwise, alone or in combination with otherterms, refer to an element, surface, or assembly being situated, orfacing, away from, the centerline axis along a radius, which may beradius 240 or parallel to, or coplanar with radius 240. The terms“inward” and “inwardly” and the terms “outward” and “outwardly” mayrefer to opposite directions along a radius projecting perpendicularlyfrom the centerline axis.

The terms “circumferential” and “circumferentially,” as used herein,unless stated otherwise, alone or in combination with other terms, referto elements, surfaces, or assemblies relative to one another encirclinga centerline axis at a radius. Alternatively, or in addition, the terms“circumferential” and “circumferentially,” as used herein, unless statedotherwise, alone or in combination with other terms, mean relating to acircumference of a circle centered on, and perpendicular to, acenterline axis.

The terms “cast” and “casting,” as used herein, unless statingotherwise, alone or in combination with other terms, refer to a processin which a liquid metal is delivered into a mold that contains anegative impression, or three-dimensional negative image) of an intendedshape through a sprue, followed by cooling of the metal and mold.

The terms “injection molding” and “injection molded,” as used herein,unless stated otherwise, alone or in combination with other terms, referto a process for producing parts by injecting molten material includingmetals, glasses, elastomers, confections, and thermoplastic orthermosetting polymers into a mold cavity, where the molten materialcools and hardens to the configuration of the cavity. Advances inthree-dimensional printing technology have resulted in photopolymersthat do not melt during the injection molding of lower temperaturethermoplastics being used for some simple injection molds.

The terms “three-dimensionally printing” and “three-dimensionallyprinted,” as used herein, unless stated otherwise, alone or incombination with other terms, refer to a variety of processes in whichmaterial is joined or solidified under computer control to create athree-dimensional object or part, which material being added together,such as liquid molecules or powder grains being fused together,typically layer by layer.

The terms “abrasive machining” and “abrasively machined,” as usedherein, unless stated otherwise, alone or in combination with otherterms, refer to a machining process where material is removed from aworkpiece using a multitude of small abrasive particles by forcing theabrasive particles, or grains, into the surface of the workpiece so thateach particle cuts away a small bit of material. Common examples ofabrasive machining include grinding, honing, and polishing.

The term “conduction,” as used herein, unless stated otherwise, alone orin combination with other terms, refers to a transfer of internal energyby microscopic collisions of particles and movement of electrons withina body. The colliding particles, which include molecules, atoms, andelectrons, transfer disorganized microscopic kinetic and potentialenergy. The rate at which energy is conducted as heat between two bodiesdepends on the temperature difference and the properties of theconductive interface through which the heat is transferred. Inconduction, heat flow is within and through the body itself.

Examples of compressor turbine wheels of the present disclosure may becomposed of metal and/or ceramic material. Examples of metals mayinclude, but are not limited to, titanium, such as high-temperatureArconic-Thor, or a nickel-based superalloy, such as IN718, or MarM247.Examples of ceramics may include, but are not limited to, monolithicceramics, such as silicon nitride, or composite ceramics, such asSiC—SiC ceramic matrix composite (“CMC”).

In the context of the present disclosure, a first piece is said to be“integral” to a second piece if the first and second pieces are formedas a single piece. For example, if the first and second pieces are castas a single metal or metal alloy piece, then the first piece is integralto the second piece. However, if the first and second pieces areseparately formed, and subsequently attached or fixed together, then thefirst piece is not integral to the second piece.

All methods described herein may be performed in any suitable orderunless otherwise indicated herein or otherwise clearly contradicted bycontext.

To clarify the use of and to hereby provide notice to the public, thephrases “at least one of <A>, <B>, . . . and <N>” or “at least one of<A>, <B>, . . . <N>, or combinations thereof” or “<A>, <B>, . . . and/or<N>” are defined by the Applicant in the broadest sense, superseding anyother implied definitions hereinbefore or hereinafter unless expresslyasserted by the Applicant to the contrary, to mean one or more elementsselected from the group comprising A, B, . . . and N. In other words,the phrases mean any combination of one or more of the elements A, B, .. . or N including any one element alone or the one element incombination with one or more of the other elements which may alsoinclude, in combination, additional elements not listed. Unlessotherwise indicated or the context suggests otherwise, as used herein,“a” or “an” means “at least one” or “one or more.” These terms, whichrefer to the inclusion of a single element or a plurality of theelements, may also be represented by the suffix “(s)” at the end of theelement.

While various examples have been described, it will be apparent to thoseof ordinary skill in the art that many more examples and implementationsare possible. Accordingly, the examples described herein are not theonly possible implementations.

The subject-matter of the disclosure may also relate, among others, tothe following aspects:

A first aspect relates to a compressor turbine wheel for a gas turbineengine, the compressor turbine wheel rotatable about a forward-aft axispassing through a forward-aft axial wheel bore at a center of thecompressor turbine wheel, the compressor turbine wheel comprising: acompressor impeller comprising a forward impeller vane inlet, a radialimpeller vane outlet configured to flow compressed air radially outwardto a diffuser, an aft inner surface extending from the forward impellervane inlet to the radial impeller vane outlet, and inner vane side wallsprojecting forward from the aft inner surface; and a radial inflowturbine aft of the compressor impeller and comprising a radial turbinevane inlet configured to receive combustion gases from a combustor, anaft turbine vane outlet, a forward inner turbine surface extending fromthe radial turbine vane inlet to the aft turbine vane outlet, and innerturbine vane side walls projecting aft from the forward inner turbinesurface; and wherein the radial inflow turbine is integral to thecompressor impeller or an aft outer surface of the compressor impelleris fixed to a forward outer surface of the radial inflow turbine.

A second aspect relates to the compressor turbine wheel of aspect 1,wherein the aft inner surface and/or the inner vane side walls comprisea rib configured to increase surface area of the aft inner surfaceand/or the inner vane side walls.

A third aspect relates to the compressor turbine wheel of any precedingaspect, wherein the forward inner turbine surface and/or the innerturbine vane side walls comprise a pin, a rib, a vane, and/or aturbulator configured to increase surface area of the forward innerturbine surface and/or the inner turbine vane side walls.

A fourth aspect relates to the compressor turbine wheel of any precedingaspect, wherein a passage extends between the aft inner surface and theforward inner turbine surface, the passage configured to provide directflow of air between the compressor impeller and the radial inflowturbine.

A fifth aspect relates to the compressor turbine wheel of aspect 4,wherein two or more passages extend between the aft inner surface andthe forward inner turbine surface configured to circulate air betweenthe compressor impeller and the radial inflow turbine.

A sixth aspect relates to the compressor turbine wheel of aspect 4,wherein a second passage extends between the aft inner surface and theforward inner turbine surface; wherein the passage is configured todirect flow of air from the compressor impeller to the radial inflowturbine to cool the radial inflow turbine; and wherein the secondpassage is configured to return flow of air from the radial inflowturbine to the compressor impeller.

A seventh aspect relates to the compressor turbine wheel of anypreceding aspect, wherein the compressor turbine wheel is configured tocool the radial inflow turbine by conduction from the radial inflowturbine to the compressor impeller.

An eighth aspect relates to the compressor turbine wheel of anypreceding aspect, wherein the compressor turbine wheel is cast,injection molded, three-dimensionally printed, or abrasively machined.

A ninth aspect relates to the compressor turbine wheel of any precedingaspect, wherein the compressor turbine wheel is metal or ceramic.

A tenth aspect relates to the compressor turbine wheel of any precedingaspect, wherein a forward outer surface of the radial inflow turbine isbrazed or welded to an aft outer surface of the compressor impeller.

An eleventh aspect relates to a method of cooling a radial inflowturbine of a gas turbine engine rotatable about a forward-aft axis,comprising: transferring heat from the radial inflow turbine to acompressor impeller via conduction through the radial inflow turbine andthe compressor impeller; and wherein the radial inflow turbine isintegral to the compressor impeller, or an aft outer surface of thecompressor is fixed to a forward outer surface of the radial inflowturbine.

A twelfth aspect relates to the method of aspect 11, wherein thetransferring comprises: conducting heat from the radial inflow turbineto the compressor impeller.

A thirteenth aspect relates to the method of aspect 11, wherein thetransferring comprises: flowing air aft form the compressor impeller tothe radial inflow turbine through a passage between an aft inner surfaceof the compressor impeller and a forward inner turbine surface of theradial inflow turbine, the aft inner surface extending from a forwardimpeller vane inlet to a radial impeller vane outlet, the forward innerturbine surface extending from a radial turbine vane inlet to an aftturbine vane outlet.

A fourteenth aspect relates to the method of aspects 11 and 13, whereinthe transferring comprises: flowing air forward from the radial inflowturbine to the compressor impeller through a second passage between theaft inner surface and the forward inner surface.

A fifteenth aspect relates to the method of aspects 11 to 14, furthercomprising: increasing turbulence of air flowing through the radialinflow turbine.

In addition to the features mentioned in each of the independent aspectsenumerated above, some examples may show, alone or in combination, theoptional features mentioned in the dependent aspects and/or as disclosedin the description above and shown in the figures.

What is claimed is:
 1. A compressor turbine wheel for a gas turbineengine, the compressor turbine wheel rotatable about a forward-aft axispassing through a forward-aft axial wheel bore at a center of thecompressor turbine wheel, the compressor turbine wheel comprising: acompressor impeller comprising a forward impeller vane inlet, a radialimpeller vane outlet configured to flow compressed air radially outwardto a diffuser, an aft inner surface extending from the forward impellervane inlet to the radial impeller vane outlet, and inner vane side wallsprojecting forward from the aft inner surface; and a radial inflowturbine aft of the compressor impeller and comprising a radial turbinevane inlet configured to receive combustion gases from a combustor, anaft turbine vane outlet, a forward inner turbine surface extending fromthe radial turbine vane inlet to the aft turbine vane outlet, and innerturbine vane side walls projecting aft from the forward inner turbinesurface; and wherein the radial inflow turbine is integral to thecompressor impeller.
 2. The compressor turbine wheel of claim 1, whereinthe aft inner surface and/or the inner vane side walls comprise a ribconfigured to increase surface area of the aft inner surface and/or theinner vane side walls.
 3. The compressor turbine wheel of claim 1,wherein the forward inner turbine surface and/or the inner turbine vaneside walls comprise a pin, a rib, a vane, and/or a turbulator configuredto increase surface area of the forward inner turbine surface and/or theinner turbine vane side walls.
 4. The compressor turbine wheel of claim1, wherein a passage extends between the aft inner surface and theforward inner turbine surface, the passage configured to provide directflow of air between the compressor impeller and the radial inflowturbine.
 5. The compressor turbine wheel of claim 1, wherein thecompressor turbine wheel is configured to cool the radial inflow turbineby conduction from the radial inflow turbine to the compressor impeller.6. The compressor turbine wheel of claim 1, wherein the compressorturbine wheel is cast, injection molded, three-dimensionally printed, orabrasively machined.
 7. The compressor impeller of claim 1, wherein thecompressor turbine wheel is metal or ceramic.
 8. A compressor turbinewheel for a gas turbine engine, the compressor turbine wheel rotatableabout a forward-aft axis passing through a forward-aft axial wheel boreat a center of the compressor turbine wheel, the compressor turbinewheel comprising: a compressor impeller comprising a forward impellervane inlet, a radial impeller vane outlet configured to flow compressedair radially outward to a diffuser, an aft inner surface extending fromthe forward impeller vane inlet to the radial impeller vane outlet, andinner vane side walls projecting forward from the aft inner surface; anda radial inflow turbine aft of the compressor impeller and comprising aradial turbine vane inlet configured to receive combustion gases from acombustor, an aft turbine vane outlet, a forward inner turbine surfaceextending from the radial turbine vane inlet to the aft turbine vaneoutlet, and inner turbine vane side walls projecting aft from theforward inner turbine surface; wherein the radial inflow turbine isintegral to the compressor impeller, or an aft outer surface of thecompressor impeller is fixed to a forward outer surface of the radialinflow turbine; and wherein a passage extends between the aft innersurface and the forward inner turbine surface.
 9. The compressor turbinewheel of claim 8, wherein the passage is configured to provide coolingair from the compressor impeller to the radial inflow turbine.
 10. Thecompressor turbine wheel of claim 8, wherein the aft inner surfaceand/or the inner vane side walls comprise a rib configured to increasesurface area of the aft inner surface and/or the inner vane side walls.11. The compressor turbine wheel of claim 8, wherein the forward innerturbine surface and/or the inner turbine vane side walls comprise a pin,a rib, a vane, and/or a turbulator configured to increase surface areaof the forward inner turbine surface and/or the inner turbine vane sidewalls.
 12. The compressor turbine wheel of claim 8, wherein a forwardouter surface of the radial inflow turbine is brazed or welded to an aftouter surface of the compressor impeller.
 13. The compressor turbinewheel of claim 8, wherein two or more passages extend between the aftinner surface and the forward inner turbine surface configured tocirculate air between the compressor impeller and the radial inflowturbine.
 14. The compressor turbine wheel of claim 8, wherein a secondpassage extends between the aft inner surface and the forward innerturbine surface; wherein the passage is configured to direct flow of airfrom the compressor impeller to the radial inflow turbine to cool theradial inflow turbine; and wherein the second passage is configured toreturn flow of air from the radial inflow turbine to the compressorimpeller.
 15. The compressor impeller of claim 8, wherein the compressorturbine wheel is metal or ceramic.
 16. A method of cooling a radialinflow turbine of a gas turbine engine rotatable about a forward-aftaxis, comprising: transferring heat from the radial inflow turbine to acompressor impeller via conduction through the radial inflow turbine andthe compressor impeller; and wherein the radial inflow turbine isintegral to the compressor impeller, or an aft outer surface of thecompressor impeller is fixed to a forward outer surface of the radialinflow turbine.
 17. The method of claim 16, wherein the transferringcomprises: conducting heat from the radial inflow turbine to thecompressor impeller.
 18. The method of claim 16, wherein thetransferring comprises: flowing air aft from the compressor impeller tothe radial inflow turbine through a passage between an aft inner surfaceof the compressor impeller and a forward inner turbine surface of theradial inflow turbine, the aft inner surface extending from a forwardimpeller vane inlet to a radial impeller vane outlet, the forward innerturbine surface extending from a radial turbine vane inlet to an aftturbine vane outlet.
 19. The method of claim 16, wherein thetransferring comprises: flowing air aft from the compressor impeller tothe radial inflow turbine through a passage between an aft inner surfaceof the compressor impeller and a forward inner turbine surface of theradial inflow turbine, the aft inner surface extending from a forwardimpeller vane inlet to a radial impeller vane outlet, the forward innerturbine surface extending from a radial turbine vane inlet to an aftturbine vane outlet; and flowing air forward from the radial inflowturbine to the compressor impeller through a second passage between theaft inner surface and the forward inner turbine surface.
 20. The methodof claim 16, further comprising: increasing turbulence of air flowingthrough the radial inflow turbine.